document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=264581>Question 264581</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A multiple choice test has 20 questions with each having 4 possible answers with one correct. Assume a student randomly guesses the answer to every question<BR>\n" );
document.write( "a. What is the probability of getting exactly 9 correct answers?<BR>\n" );
document.write( "b. What is the probability of getting less than 9 correct answers? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #194779 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=194779\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  A multiple choice test has 20 questions with each having 4 possible answers with one correct. Assume a student randomly guesses the answer to every question<BR>\n" );
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document.write( "Binomial Problem with n = 20, p = 1/4<BR>\n" );
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document.write( "a. What is the probability of getting exactly 9 correct answers?<BR>\n" );
document.write( "P(x=9) = 20C9(1/4)^9(3/4)^11) = 0.02706...<BR>\n" );
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document.write( "b. What is the probability of getting less than 9 correct answers?<BR>\n" );
document.write( "P(0<= x <=8) = binomcdf(20,4^-1,8) = 0.9591...<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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